Analgesic use of N-L-α-aspartyl-L-phenylalanine 1-methyl ester

ABSTRACT

N-L- alpha -aspartyl-L-phenylalanine 1-methyl ester and/or its derivatives has been found to have analgesic pain relieving properties. It has been found to be especially effective in relieving pain associated with osteoarthritis and multiple sclerosis. It can be administered by itself or in combination with other analgesics. When given in combination with other analgesics, N-L- alpha -aspartyl-L-phenylalanine 1-methyl ester and/or its derivatives helps to alleviate the detrimental side effects of other analgesic medications by lowering the dosage requirements for pain relief.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of prior filed copending U.S. Provisional Application Ser. No. 60/000479 filed Jun. 23, 1995.

TECHNICAL FIELD

The present invention relates to pain relieving composition and a method for use.

BACKGROUND OF THE INVENTION

Pain is the most common symptom for which patients seek medical assistance. In the case of incurable diseases, treatment for pain may last for extended periods of time. Pain is both a physical and an emotional experience which differs greatly from one individual to another. Although subjective, most pain is associated with tissue damage and has a physiological basis.

Pain can be either acute or chronic. Acute pain is generally caused by sudden injury, tissue damage, or infection for which the cause is easily found. Chronic pain, however, is the pain of pathological conditions and often difficult to isolate and treat. Chronic pain is routinely defined as pain of over six months duration.

For patients suffering from chronic pain, the autonomic nervous system adapts to the pain and evidences of autonomic hyperactivity such as tachycardia, hypertension, diaphoresis, mydriasis, and pallor disappear, leaving the physician to rely on the patient's subjective complaints in assessing chronic pain.

In the management of chronic pain, some types of pain permit treatment of the underlying disorder, i.e., radiation treatment for pain caused by bone cancer. In some cases, a particular treatment is given for a specific type of pain, i.e., treatment of trigeminal neuralgia or glossopharyngeal neuralgia with carbamazepine, reflex sympathetic dystrophies with local anesthetic, postherpetic neuralgia with direct stimulation.

In many patients, however, the pain is chronic and the physician can neither treat the underlying disturbance nor prescribe a specific therapy for that type of pain. For example, osteoarthritis is a joint disease characterized by degeneration and loss of articular cartilage and by osteophyte formation, or bony outgrowth of subchondral bone. The disease is slowly progressive, leading to chronic pain and stiffness and gradually to increasing dysfunction of the affected joint. The incidence of the disease increases with age and affects three times as many women as men.

Chronic joint pain, swelling, creaking, and stiffness are the most prominent symptoms of osteoarthritis. The disease commonly affects the distal interphalangeal joints of the hands, resulting in bone enlargements often accompanied by inflammation and pain. Weight bearing joints such as the neck, lower back, knees and hips are often affected by this type of arthritis.

Another major symptom of osteoarthritis is loss of articulation of the joint. Weakness and shrinkage of surrounding muscles may occur if pain prevents the joint from being used regularly. As movement of an affected joint becomes severely limited, the sufferer experiences loss of functionality of the joint. In the case of osteoarthritis of the hip or knees, ambulation becomes impaired.

Although osteoarthritis is the most common of the rheumatic diseases, its pathogenesis is not well understood, and currently there is no treatment that will retard or reverse pathological processes in the disease. The only treatment available to osteoarthritis sufferers has involved symptomatic treatment through analgesics for pain and nonsteroidal anti-inflammatory agents for reduction of joint inflammation. An injection of a corticosteroid may also be administered to a painful joint.

Chronic pain is also associated with multiple sclerosis (MS), also known as disseminated or insular sclerosis, a disease of the central nervous system (CNS) characterized by widespread patches of demyelination in the brain and spinal cord. The disease occurs worldwide in about 10-60 persons per 100,000 with the age at onset occurring at about 20-40 years, and appears to affect females more often than males. While MS is generally chronic and relapsing, fulminating attacks occur, and as many as 30% of the patients progress steadily from the onset.

Although multiple sclerosis is the most common demyelinating disease, its cause is unknown, and there is no treatment to retard or reverse the pathological processes of the disease. There is no specific therapy recommended because spontaneous remissions make treatment difficult to evaluate. The only treatment available to multiple sclerosis patients include corticosteroid therapy (e.g., prednisone or dexamethasone) until manifestations remit, and symptomatic treatment such as baclofen for spasticity and pain relievers such as analgesics and opiates.

There are several types of drugs used to decrease chronic pain. Analgesics are drugs used to decrease pain without causing loss of consciousness or sensory perception. There are two basic classes of analgesics: anti-inflammatory, routinely prescribed for short-term pain relief and for modest pain, and opioids used for either short-term or long term pain relief of severe pain. The anti-inflammatory analgesics generally provide analgesia, anti-inflammation, and antipyretic action. It has been reported that the mechanism of action may be to provide inhibition of the synthesis of prostaglandins. W. W. Douglas, "Polypeptides--angiotensin, plasma kinins, and other vasoactive agents; prostaglandins," The Pharmacological Basis of Therapeutics, 9th edition, L. S. Goodman and A. Gilman (eds.), MacMillan Publishing Co., Inc., New York, 1975. Prolonged use of anti-inflammatory analgesics have been known to cause gastrointestinal problems.

The opioid analgesics, or narcotics, include all natural or synthetic chemical compounds closely related to morphine and are thought to activate one or more receptors on brain neurons. Opioid analgesics have serious side effects and thus are used with discrimination. These side effects include: 1) tolerance, which requires gradually increasing doses to maintain analgesia; 2) physical dependence, which means that the narcotics must be withdrawn gradually if they are discontinued after prolonged use; 3) constipation, which requires careful attention to bowel function, including use of stool softeners, laxatives, and enemas; and 4) various degrees of somnolence, or drowsiness, which requires adjustments in dosages and dose scheduling, or possibly varying the type of narcotic to find one better tolerated by the patient.

It has been reported that various treatments for pain are additive and should be used together rather than separately. For example, the combination of aspirin or acetaminophen and codeine is often prescribed to provide pain relief stronger than codeine by itself. Certain antidepressants prescribed for depression have been recommended as an analgesic adjuvant.

While pain management has been a problem faced by physicians for many years, available pain medications have ameliorated, but not alleviated the problem of pain treatment. A significant problem remains in that detrimental side effects are often caused by pain-relieving medications as detailed above. Thus, there remains a continuing need for alternative pain therapy regimens which would address the need for pain reduction but also reduce these side effects.

Surprisingly, it has now been discovered that N-L-α-aspartyl-L-phenylalanine 1-methyl ester and derivatives have analgesic properties, relieving pain and restoring function of soft tissues, muscles, ligaments, tendons, bones, and joints. Further, when taken in combination with other analgesic agents, N-L-α-aspartyl-L-phenylalanine 1-methyl ester provides an additive analgesic effect. The detrimental side effects inherent in pain therapy known to the art can be reduced through the use of N-L-α-aspartyl-L-phenylalanine 1-methyl ester in pain therapy and management.

SUMMARY OF THE INVENTION

In one aspect of the invention, N-L-α-aspartyl-L-phenylalanine 1-methyl ester or its derivatives or both are used in a method for decreasing pain in a human patient.

In another aspect, N-L-α-aspartyl-L-phenylalanine 1-methyl ester or its derivatives or both are used in combination with an anti-inflammatory analgesic drug of other composition in a pain treatment regimen.

In another aspect, N-L-α-aspartyl-L-phenylalanine 1-methyl ester or its derivatives or both are used in combination with an opioid analgesic in a pain treatment regimen.

In yet another aspect, N-L-α-aspartyl-L-phenylalanine 1-methyl ester or its derivatives or both are used in treating osteoarthritis.

Another aspect of the invention concerns pharmaceutical dosage form containing N-L-α-aspartyl-L-phenylalanine 1-methyl ester or its derivatives or both.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a graph depicting the average time required to ascend and descend stairs for the APM and control treatment groups measured over time.

FIG. 2 is a graph depicting the average pain experienced by the APM and control treatment groups upon ascending and descending stairs measured over time.

FIG. 3 is a graph depicting the average rest pain experienced by the APM and control treatment groups taken after a one hour rest period following ascending and descending stairs measured over time.

FIG. 4 is a graph depicting the difference between stair pain and rest pain experienced by the APM and control treatment groups upon ascending and descending stairs measured over time.

FIG. 5 is a graph depicting the average distance walked by the APM and control treatment groups measured over time.

FIG. 6 is a graph depicting the average pain experienced by the APM and control treatment groups upon walking for five minutes measured over time.

FIG. 7 is a graph depicting the average grip strength for the APM and control treatment groups measured over time.

FIG. 8 is a graph depicting the average gripping pain experienced by the APM and control treatment groups measured over time.

DETAILED DESCRIPTION

Chronic pain has been shown to be associated with various pathological conditions such as osteoarthritis, inflammation, multiple sclerosis, and myocardial infarction. It has now been found that N-L-α-aspartyl-L-phenylalanine 1-methyl ester (APM), which has been sold under the trade name of ASPARTAME™ (G. D. Searle & Company, Chicago, Ill.) and its derivatives offer medicinal qualities beneficial in the treatment of chronic pain. One can use an effective amount of APM to effect a reduction in perceived pain by the recipient within one hour of dosage. The effective amount per dosage is about 40 milligrams to about 540 milligrams. An effective amount of APM which can effect pain relief after one dose is from about 80 milligrams to about 320 milligrams. A preferred range is from about 80 milligrams to about 160 milligrams. Most preferred is about 160 milligrams. The dosage can be repeated over time for continued relief, preferably at 160 milligrams every 4 hours. APM can also be administered together with other analgesics such as acetaminophen, phenacetin, aspirin, ibuprofen, phenylbutazone, indomethacin and derivatives, opiates and derivatives, piroxacam, and steroidal and nonsteroidal anti-inflammatory agents, providing additive analgesic properties.

APM can be administered orally, parenterally, intraperitoneally, or sublingually. It can be administered via ingestion of a food substance containing APM in a volume sufficient to achieve therapeutic levels. Alternatively, it can be enclosed in capsules, compressed into tablets, microencapsulated, entrapped in liposomes, in solution or suspension, alone or in combination with a substrate immobilizing material such as starch or poorly absorbable salts. Pharmaceutically compatible binding agents and/or adjuvant materials can be used as part of a composition. Tablets or capsules can contain any of the following ingredients, or compounds of similar nature: a binder such as microcrystalline cellulose, gum tragacanth or gelatin; an excipient such as starch or lactose; an integrating agent such as alginic acid, corn starch; a lubricant such as magnesium stearate; a glidant such as colloidal silicon dioxide; and additional sweetening and flavoring agents. When a capsule form is used the liquid carrier such as a fatty oil may be used. Capsules and tablets can be coated with sugar, shellac and other enteric agents as is known. APM can also be in a controlled-release formulation.

APM is available commercially. Its preparation is also disclosed in U.S. Pat. No. 3,492,131. It is believed that various modifications can be made to the APM molecule and the resulting derivatives will also have utility in the claimed invention. Since the 1-methyl ester portion of the molecule is not believed to contribute to the analgesic activity of the molecule, N-L-α-aspartyl-L-phenylalanine itself or other lower alkyl esters are believed to be effective. Other possible analgesic physiologically acceptable derivatives are believed to include N-acyl-L-(beta-substituted)-aspartyl-L-phenylalanine lower alkyl esters and N-acyl-L-(beta-substituted)-aspartyl-L-phenylalanine. Chemical modifications made to the APM molecule which do not reduce the analgesic physiologically active properties disclosed herein thus fall within the scope of this invention.

EXAMPLE 1

Osteoarthritis

In a well-controlled double-blind crossover study, patients suffering from osteoarthritis were given the tasks of climbing stairs, walking, and hand gripping, all of which are known to cause chronic pain in osteoarthritic patients, following treatment with either APM or a placebo. The study was performed twice for all patients, and prior to each study, all other analgesics were withheld for twenty-four hours. During the first study, one test group of eleven patients were randomly administered 4 tablets of either aspartame (76 milligrams; 19 milligrams/tablet) or placebo, and another test group of nine patients were randomly given 8 tablets of either aspartame (152 milligrams; 19 milligrams/tablet) or placebo. During the second study, each patient was given the same number of tablets but were given the opposite medication from what they had received in the first study. Following each test, data analysis of the recovered information was completed using non-parametric analyses of variance and distribution free assessments of the measured variable.

Stair Climbing

Twenty osteoarthritic patients divided into groups of nine and eleven each were asked to ascend and descend one flight of stairs, making a total of three trips with one-hour rest periods between trips. Right after the first baseline trip, patients were administered the test medication. All patients then made three subsequent trips up and down the stairs. Table I and FIG. 1 present an objective measurement of performance with respect to the time required for each patient to ascend and descend one flight of stairs. The mean results show that over time the 4-tablet APM group decreased the stair time, with a 9.6% decrease for the last trip. For the 8-tablet APM group, a decrease of 11.9% was observed for the second trip after dosing and 6.9% for the last trip. After administration of the placebo, the 4-tablet placebo group showed a decrease in stair time of 6.5% for the first and second trips after dosing, and 3.7% for the last trip. The 8-tablet placebo group showed a gradual increase in stair time with a maximum increase of 2% for the last trip.

A subjective measurement of stair pain was made by administering a visual analog pain assessment to the patients. A baseline assessment for various joints, usually three joints, was taken one hour prior to the first baseline trip, and the assessment was then repeated for each of the four trips. Each patient made an assessment under a nurse's supervision (same nurse throughout study) as to the amount of pain involved on

                  TABLE I                                                          ______________________________________                                         Stair Time with and without APM                                                          Stair Climb Time (min)                                                         Hours after Treatment                                                Subject #   0      1          2    3                                           ______________________________________                                         Control group - 4 tablets placebo                                              1           1.04   0.59       0.59 1.01                                        2           0.92   0.99       0.97 0.96                                        3           1.19   1.12       1.10 1.15                                        4           1.00   1.03       1.04 1.04                                        5           0.90   0.91       0.94 0.98                                        6           2.09   1.50       1.51 1.56                                        7           0.79   0.79       0.80 0.81                                        8           1.28   1.27       1.23 1.24                                        9           1.25   1.26       1.26 1.26                                        10          0.72   1.02       1.01 0.80                                        11          0.56   0.58       0.54 0.55                                        mean        1.07   1.00       1.00 1.03                                        APM group - 4 tablets APM                                                      1           1.05   1.01       1.00 1.01                                        2           0.96   0.96       0.93 0.88                                        3           1.10   1.08       1.04 1.02                                        4           1.10   1.10       1.07 1.06                                        5           0.90   0.91       0.89 0.92                                        6           2.07   2.10       2.16 1.54                                        7           0.78   0.79       0.79 0.78                                        8           1.36   1.30       1.28 1.33                                        9           1.23   1.25       1.24 1.25                                        10          1.01   1.02       1.02 1.02                                        11          1.07   1.03       1.01 0.59                                        mean        1.15   1.14       1.13 1.04                                        Control group - 8 tablets placebo                                              12          0.94   0.94       0.91 0.93                                        13          0.90   0.92       0.90 0.96                                        14          1.44   1.43       1.51 1.56                                        15          0.49   0.51       0.54 0.58                                        16          1.24   1.25       1.25 1.22                                        17          1.07   1.07       1.13 1.13                                        18          1.14   1.11       1.09 1.10                                        19          0.81   0.84       0.83 0.84                                        20          1.15   1.08       1.08 1.05                                        mean        1.02   1.02       1.03 1.04                                        APM group - 8 tablets APM                                                      12          0.94   0.92       0.89 0.86                                        13          0.87   0.88       0.89 0.90                                        14          1.45   1.42       1.35 1.44                                        15          0.50   0.55       0.56 0.51                                        16          1.33   1.25       1.27 1.25                                        17          1.00   1.03       0.55 0.59                                        18          1.14   1.16       1.08 1.08                                        19          0.84   0.88       0.86 0.83                                        20          1.06   1.02       0.58 1.00                                        mean        1.01   1.01       0.89 0.94                                        Total mean score by treatment group                                            Control     1.05   1.01       1.01 1.04                                        APM         1.09   1.08       1.02 0.99                                        ______________________________________                                    

a scale marked with increments for none, a little, more, a lot, and most. A numerical conversion of the marks on the scale in millimeters taken as the distance from the absence of pain mark were made. The representation of this assessment scale where the lower the number the lesser the pain, and the higher the number, the greater the pain is given in Table II and FIG. 2 as an average value for all rated joints. Referring to the mean, there was a marked decrease in the amount of pain associated with ascending and descending stairs in the APM groups in comparison to that in the placebo groups. The 4-tablet placebo group showed increased pain over the pre-climbing baseline assessment for each trip; however, while the 4-tablet APM group also experienced increased pain over the pre-climbing baseline assessment for the first two trips, they had decreased pain below or just above the pre-climbing baseline assessment for the last two trips.

Table III provides pain assessment measurements for the most sensitive joint for some of the patients taken at one hour and two hours after treatment. For the 4-tablet treatment groups, the placebo group showed a slight increase in pain (2.2%), while the APM group experienced a 52.2% decrease in pain. The 8-tablet APM group also experienced a significant decrease in pain (48.2%), compared to a 24.5% decrease in pain for the 8-tablet placebo group.

An evaluation of pain was also measured using the visual analog pain assessment method by the patient at the end of each rest period (Table IV and FIG. 3).

                  TABLE II                                                         ______________________________________                                         Stair Pain with and without APM                                                Stair Pain (relative numerical scale)                                          Hours after Treatment                                                          Subject #                                                                             -1        0       1       2     3                                       ______________________________________                                         Control group - 4 tablets placebo                                              1      27        24      33      42    36                                      2      62        102     119     91    74                                      3      51        85      67      110   73                                      4      31        73      25      32    31                                      5      42        59      38      73    58                                      6      93        117     118     126   127                                     7      24        81      97      89    88                                      8      41        22      31      28    21                                      9      31        46      64      45    75                                      10     55        72      78      88    85                                      11     36        48      50      31    36                                      mean   44.82     68.55   65.45   68.64 64.00                                   APM group - 4 tablets APM                                                      1      45        47      48      36    22                                      2      24        80      91      32    38                                      3      106       130     130     73    73                                      4      79        63      70      40    42                                      5      41        71      56      56    44                                      6      46        95      130     101   130                                     7      28        87      87      56    74                                      8      59        28      30      28    62                                      9      94        56      47      30    30                                      10     67        83      96      91    105                                     11     36        45      49      52    24                                      mean   56.82     71.36   75.82   54.09 58.55                                   Control group - 8 tablets placebo                                              12     33        66      60      51    59                                      13     22        40      26      30    24                                      14     35        74      115     116   118                                     15     45        74      21      33    50                                      16     50        52      50      51    56                                      17     22        28      26      22    21                                      18     62        74      92      77    74                                      19     8         49      63      49    83                                      20     43        45      33      20    21                                      mean   35.56     55.78   54.00   49.89 56.22                                   APM group - 8 tablets APM                                                      12     42        72      71      51    53                                      13     31        31      39      31    31                                      14     69        97      84      85    117                                     15     33        35      23      31    33                                      16     53        52      54      53    54                                      17     39        31      15      21    17                                      18     25        48      65      49    56                                      19     57        78      63      72    74                                      20     34        37      26      14    14                                      mean   42.56     53.44   48.89   45.22 49.89                                   Total mean score by treatment group                                            Control                                                                               40.65     62.80   60.30   60.20 60.50                                   APM    50.40     63.30   63.70   50.10 54.65                                   ______________________________________                                    

                  TABLE III                                                        ______________________________________                                         Stair Pain of Most Sensitive Joint                                             with and without APM                                                                     Stair Pain (relative numerical scale)                                          Hours after Treatment                                                Subject #   1           2                                                      ______________________________________                                         Control group - 4 tablets placebo                                              1           24          43                                                     2           113         105                                                    3           63          92                                                     4           25          32                                                     5           21          57                                                     6           149         149                                                    7           97          77                                                     8           16          21                                                     9           73          35                                                     10          --          --                                                     11          33          17                                                     mean        61.40       62.80                                                  APM group - 4 tablets APM                                                      1           53          35                                                     2           107         53                                                     3           130         16                                                     4           104         46                                                     5           56          22                                                     6           150         106                                                    7           75          39                                                     8           45          26                                                     9           73          37                                                     10          --          --                                                     11          32          14                                                     mean        82.50       39.40                                                  Control group - 8 tablets placebo                                              12          48          39                                                     13          26          38                                                     14          --          --                                                     15          --          --                                                     16          --          --                                                     17          --          --                                                     18          129         93                                                     19          86          58                                                     20          33          15                                                     mean        64.40       48.60                                                  APM group - 8 tablets APM                                                      12          71          11                                                     13          55          39                                                     14          --          --                                                     15          --          --                                                     16          --          --                                                     17          --          --                                                     18          32          15                                                     19          86          72                                                     20          36          8                                                      mean        56.00       29.00                                                  Total mean score by treatment group                                            Control     62.40       58.07                                                  APM         73.67       35.93                                                  ______________________________________                                    

                  TABLE IV                                                         ______________________________________                                         Rest Pain with and without APM                                                         Rest Pain (relative numerical scale)                                           Hours after Treatment                                                  Subject # 0       1           2     3                                          ______________________________________                                         Control group - 4 tablets placebo                                              1         27      31          32    45                                         2         62      79          36    48                                         3         51      10          30    15                                         4         31      46          30    30                                         5         42      54          40    41                                         6         93      116         127   129                                        7         24      39          42    40                                         8         41      35          23    16                                         9         31      31          48    58                                         10        55      70          73    80                                         11        36      35          32    25                                         mean      44.82   49.64       46.64 47.91                                      APM group - 4 tablets APM                                                      1         45      37          45    17                                         2         24      50          77    78                                         3         106     25          14    30                                         4         79      68          56    40                                         5         41      40          39    41                                         6         46      77          94    99                                         7         28      9           8     39                                         8         59      49          25    27                                         9         94      77          32    24                                         10        67      80          89    96                                         11        36      38          43    69                                         mean      56.82   50.00       47.45 50.91                                      Control group - 8 tablets placebo                                              12        33      34          16    14                                         13        22      24          28    32                                         14        35      78          115   118                                        15        45      19          32    32                                         16        50      53          50    50                                         17        22      19          18    24                                         18        62      35          30    34                                         19        8       8           8     10                                         20        43      36          26    24                                         mean      35.56   34.00       35.89 37.56                                      APM group - 8 tablets APM                                                      12        42      58          32    38                                         13        31      32          28    33                                         14        69      73          53    86                                         15        33      20          19    27                                         16        53      54          52    52                                         17        39      35          20    16                                         18        25      33          12    20                                         19        57      39          9     39                                         20        34      30          17    16                                         mean      42.56   41.56       26.89 36.33                                      Total mean score by treatment group                                            Control   40.65   42.60       41.80 43.25                                      APM       50.40   46.20       38.20 44.35                                      ______________________________________                                    

While the average rest pain generally increased for both placebo groups, the 4-tablet APM group experienced a 12.2%, 16.5%, and 10.4% decrease in rest pain from pretreatment over time, while the 8-tablet APM group, a 5 2.3%, 36.8% and 14.6% decrease. In Table V and FIG. 4 the mean difference between stair pain and rest pain for each patient at each time period is given, showing that the mean difference of the APM groups was lower than the placebo groups. As indicated by the negative numbers, some patients in both groups experienced greater rest pain than stair climb pain.

Walking Distance

Chronic pain was examined in respect to distance walking at a comfortable speed for a five minute period. A pre-walking baseline pain assessment was performed. After establishing a baseline walking distance, the 4- and 8-tablet APM groups were given 76 milligrams and 152 milligrams APM, respectively, while the 4- and 8-tablet control groups were given the appropriate number of placebo tablets. After resting for one hour, the patients repeated the 5-minute walking procedure three times with one hour rest periods between trips. Table VI and FIG. 5 show the total distance walked in terms of feet traveled. The average distance walked in the control groups decreased slightly over time, with the mean varying from -0.5% to -2.2% from baseline. Comparatively, the average distance walked in the APM groups varied from -0.4% to 1.8% from baseline. Although the average distance

                  TABLE V                                                          ______________________________________                                         Stair Pain v. Rest Pain with and without APM                                             Stair Pain Minus Rest Pain                                                     Hours after Treatment                                                Subject #   0      1           2    3                                          ______________________________________                                         Control groups - 4 or 8 tablets placebo                                        1           22     1           10   -9                                         2           40     40          55   26                                         3           34     57          80   58                                         4           42     -21         2    1                                          5           17     -16         33   17                                         6           24     2           -1   -2                                         7           57     58          47   48                                         8           -19    -4          5    5                                          9           15     33          -3   17                                         10          17     8           15   5                                          11          12     15          -1   11                                         12          33     26          35   45                                         13          18     2           2    -8                                         14          39     37          1    0                                          15          29     2           1    18                                         16          20     -3          1    6                                          17          6      7           4    -3                                         18          12     57          47   40                                         19          41     55          41   73                                         20          2      -3          -6   -3                                         mean        23.05  17.65       18.40                                                                               17.25                                      APM groups - 4 or 8 tablets APM                                                1           2      11          -9   5                                          2           56     41          -45  -40                                        3           24     105         59   43                                         4           -16    2           -16  2                                          5           30     16          17   3                                          6           49     53          7    31                                         7           59     78          48   35                                         8           -31    -19         -2   35                                         9           -38    -30         -2   -4                                         10          16     16          2    9                                          11          -9     11          9    -45                                        12          30     13          19   15                                         13          0      7           3    -2                                         14          28     11          84   116                                        15          2      3           12   6                                          16          -1     0           1    2                                          17          -8     -20         1    1                                          18          23     32          37   36                                         19          21     25          74   35                                         20          3      -4          -3   -2                                         mean        12.90  17.55       14.78                                                                               14.06                                      ______________________________________                                    

                  TABLE VI                                                         ______________________________________                                         Walking Distance with and without APM                                                  Walking Distance (feet)                                                        Hours after Treatment                                                  Subject # 0       1          2     3                                           ______________________________________                                         Control group - 4 tablets placebo                                              1         1035    1040       1055  1045                                        2         895     875        895   825                                         3         1000    980        1030  1000                                        4         1010    980        970   990                                         5         1100    1095       1095  1120                                        6         800     775        810   800                                         7         1325    1295       1310  1295                                        8         865     900        920   890                                         9         840     865        850   810                                         10        1175    1110       1085  1100                                        11        1150    1125       1105  1100                                        mean      1017.73 1003.64    1011.36                                                                              997.73                                      APM group - 4 tablets APM                                                      1         990     1000       1000  1000                                        2         880     840        835   870                                         3         1025    1080       1090  1100                                        4         910     885        900   910                                         5         1075    1075       1070  1060                                        6         755     770        785   810                                         7         1320    1320       1325  1310                                        8         820     825        890   885                                         9         830     810        850   880                                         10        1300    1235       1245  1220                                        11        1010    1000       1025  1070                                        mean      992.27  985.45     1001.36                                                                              1010.45                                     Control group - 8 tablets placebo                                              12        935     930        920   910                                         13        1150    1160       1145  1120                                        14        780     785        760   770                                         15        1230    1250       1240  1170                                        16        900     930        940   920                                         17        1065    1025       995   1000                                        18        1095    1070       1085  1120                                        19        1350    1305       1300  1260                                        20        710     705        720   735                                         mean      1023.89 1017.78    1011.67                                                                              1000.56                                     APM group - 8 tablets APM                                                      12        980     930        910   1000                                        13        1120    1140       1115  1120                                        14        790     795        825   740                                         15        1210    1270       1260  1260                                        16        890     900        925   905                                         17        1000    995        960   1045                                        18        1075    1060       1070  1100                                        19        1285    1250       1250  1250                                        20        790     765        780   780                                         mean      1015.56 1011.67    1010.56                                                                              1022.22                                     Total mean score by treatment group                                            Control   1020.50 1010.00    1011.50                                                                              999.00                                      APM       1002.75 997.25     1005.50                                                                              1015.75                                     ______________________________________                                    

walked decreased at one hour from baseline, there was an increase at 3 hours from baseline for both APM groups.

Walking distance pain was recorded via the visual analog pain assessment. A baseline assessment was taken one hour prior to the first baseline trip. The assessment was then repeated for each of the four trips. A relative numerical representation of this assessment scale where the lower the number the lesser the pain, and the higher the number, the greater the pain is given in Table VII and FIG. 6. The average distance pain after the four walks increased over the pre-walking baseline assessment by 22.7 to 42.8% for the 4-tablet control group, and 20.6% to 35.6% for the 8-tablet control group. Comparatively, the patients in the 4-tablet APM group showed an increase in average distance pain after the baseline walk (23.0%) and the first walk after dosing (21.8%), while the average distance pain decreased below the pre-walking baseline assessment by 1.1% after the second walk after dosing and then increased to 11.4% above the pre-walking baseline assessment after the last walk. For the 8-tablet APM group, the average distance pain after the baseline walk increased over the pre-walking assessment by 24.8%; however, the average distance pain for the remaining three walks was right at or below the pre-walking baseline assessment.

                  TABLE VII                                                        ______________________________________                                         Walking Pain with and without APM                                                     Walking Pain (relative numerical scale)                                        Hours after Treatment                                                   Subject #                                                                               -1        0       1      2     3                                      ______________________________________                                         Control group - 4 tablets placebo                                              1        27        43      49     43    37                                     2        62        81      80     53    53                                     3        51        83      25     16    53                                     4        31        46      38     22    22                                     5        42        87      87     71    39                                     6        93        95      116    128   128                                    7        24        57      57     77    76                                     8        41        63      43     35    56                                     9        31        39      57     56    65                                     10       55        70      70     70    73                                     11       36        40      38     34    33                                     mean     44.82     64.00   60.00  55.00 57.73                                  APM group - 4 tablets APM                                                      1        45        60      53     33    35                                     2        24        50      62     42    99                                     3        106       118     94     32    13                                     4        79        51      63     54    59                                     5        41        71      71     73    74                                     6        46        81      93     100   100                                    7        28        58      40     37    42                                     8        59        71      86     65    85                                     9        94        83      49     29    30                                     10       67        74      86     90    100                                    11       36        52      64     63    59                                     mean     56.82     69.91   69.18  56.18 63.27                                  Control group - 8 tablets placebo                                              12       33        68      17     21    18                                     13       22        29      43     57    47                                     14       35        55      95     114   114                                    15       45        75      32     49    55                                     16       50        51      60     61    72                                     17       22        26      27     30    28                                     18       62        87      52     59    42                                     19       8         8       41     8     38                                     20       43        35      19     20    17                                     mean     35.56     48.22   42.89  46.56 47.89                                  APM group - 8 tablets APM                                                      12       42        41      30     40    40                                     13       31        47      48     47    46                                     14       69        95      84     84    96                                     15       33        38      31     36    27                                     16       53        54      61     54    56                                     17       39        35      28     27    24                                     18       25        49      55     29    44                                     19       57        75      11     40    39                                     20       34        44      24     16    13                                     mean     42.56     53.11   41.33  41.44 42.78                                  Total mean score by treatment group                                            Control  40.65     56.90   52.30  51.20 53.30                                  APM      50.40     62.35   56.65  49.55 54.05                                  ______________________________________                                    

Grip Strength

Grip strength was measured by placing the cuff into a cloth bag and filling with air to a resting pressure of 20 mmHg for easy gripping. Each patient gripped the cloth bag, and the increase in pressure registered as change in mmHg on the cuff was recorded. Following a baseline gripping measurement, the 4- and 8-tablet APM groups were given 76 milligrams and 152 milligrams APM, respectively, while the 4- and 8-tablet control groups were given the appropriate number of placebo tablets. After a one hour rest period, the gripping measurement was repeated three more times with a one hour rest period between each measurement. As shown in Table VIII and FIG. 7, both APM groups and the 4-tablet control group basically showed increasing grip strength over time. The 8-tablet control varied about 2% to 3% above and below baseline.

To determine average grip pain, a visual analog pain assessment was performed prior to the baseline gripping measurement and then repeated after each subsequent gripping measurement. In Table IX and FIG. 8, the mean data shows that within 2 hours after treatment, grip pain for both APM groups fell at or below the pre-gripping baseline assessment, while both control groups stayed at least 8% higher than the pre-gripping baseline assessment.

                  TABLE VIII                                                       ______________________________________                                         Grip Strength with and without APM                                                     Grip Strength (mmHg)                                                           Hours after Treatment                                                  Subject # 0       1          2     3                                           ______________________________________                                         Control group - 4 tablets placebo                                              1         275     280        265   260                                         2         135     110        105   105                                         3         175     170        180   170                                         4         165     180        160   170                                         5         170     195        195   180                                         6         140     155        145   200                                         7         95      80         95    95                                          8         225     235        245   275                                         9         195     205        205   245                                         10        230     230        235   225                                         11        155     160        145   160                                         mean      178.18  181.82     179.55                                                                               189.67                                      APM group - 4 tablets APM                                                      1         240     235        255   250                                         2         65      85         80    105                                         3         75      135        155   180                                         4         115     135        165   145                                         5         140     165        170   160                                         6         120     100        140   160                                         7         95      110        95    105                                         8         190     240        215   210                                         9         270     275        295   265                                         10        170     165        155   155                                         11        180     170        170   170                                         mean      150.91  165.00     172.27                                                                               173.18                                      Control group 8 tablets placebo                                                12        85      90         100   100                                         13        155     155        170   160                                         14        165     160        145   135                                         15        150     140        145   140                                         16        230     210        210   215                                         17        180     180        190   225                                         18        165     150        170   165                                         19        85      90         105   85                                          20        55      75         90    90                                          mean      141.11  138.89     147.22                                                                               146.11                                      APM group - 8 tablets APM                                                      12        80      90         95    95                                          13        145     160        160   165                                         14        125     125        120   135                                         15        155     165        165   170                                         16        235     230        220   225                                         17        185     190        195   220                                         18        110     130        160   180                                         19        110     115        100   95                                          20        75      90         85    80                                          mean      135.56  143.89     144.44                                                                               151.67                                      Total mean score by treatment group                                            Control   161.50  162.50     165.00                                                                               170.00                                      APM       144.00  155.50     159.75                                                                               163.50                                      ______________________________________                                    

                  TABLE IX                                                         ______________________________________                                         Grip Pain with and without APM                                                        Grip Pain (relative numerical scale)                                           Hours after Treatment                                                   Subject #                                                                               -1        0       1       2    3                                      ______________________________________                                         Control group - 4 tablets placebo                                              1        48        79      50      59   51                                     2        --        --      --      --   --                                     3        85        25      22      84   84                                     4        46        59      21      21   15                                     5        --        --      --      --   --                                     6        47        82      105     86   82                                     7        75        76      76      100  77                                     8        19        19      18      17   16                                     9        24        42      42      41   25                                     10       43        70      80      87   85                                     11       37        54      45      35   45                                     mean     47.11     56.22   51.00   58.89                                                                               53.33                                  APM group - 4 tablets APM                                                      1        17        45      55      22   19                                     2        --        --      --      --   --                                     3        106       106     40      20   10                                     4        47        49      33      30   35                                     5        --        --      --      --   --                                     6        46        82      106     105  93                                     7        40        58      75      75   73                                     8        16        19      19      20   17                                     9        41        42      23      24   22                                     10       71        81      91      95   107                                    11       50        53      59      50   63                                     mean     48.22     59.44   55.67   49.00                                                                               48.78                                  Control group - 8 tablets placebo                                              12       16        48      46      38   17                                     13       23        49      36      23   51                                     14       35        71      92      132  97                                     15       64        66      27      32   57                                     16       48        47      47      48   51                                     17       14        8       11      8    8                                      18       103       128     94      101  84                                     19       41        72      73      40   57                                     20       43        51      41      40   16                                     mean     43.00     60.00   51.89   51.33                                                                               48.67                                  APM group - 8 tablets APM                                                      12       16        43      74      39   15                                     13       23        23      22      20   20                                     14       34        31      71      71   72                                     15       32        35      40      48   56                                     16       18        17      16      20   17                                     17       9         13      21      24   7                                      18       88        75      90      47   71                                     19       98        97      72      74   73                                     20       75        70      36      22   17                                     mean     43.67     44.89   49.11   40.56                                                                               38.67                                  Total mean score by treatment group                                            Control  45.06     58.11   51.44   55.11                                                                               51.00                                  APM      45.94     52.17   52.39   44.78                                                                               43.72                                  ______________________________________                                    

Overall, this study documents that use of APM was successful in relieving pain and that performance was measurably improved. Statistical assessments of measured variables suggests that the inference that the observed differences were due to chance is improbable at p<0.05 to p<0.01 or more.

EXAMPLE 2

Osteoarthritis--Pain Alleviation

The analgesic properties of APM given over time was demonstrated in one osteoarthritic patient engaged in viewing a football game. The patient was in severe pain at the beginning of the game. However, upon consumption of six diet soft drinks through the course of the game (approximately 1 g APM over 3 hours), the patient experienced substantial pain relief and markedly increased joint mobility.

EXAMPLE 3

Multiple Sclerosis--Pain Alleviation

In one example of the analgesic properties of APM in combination with other analgesic agents in relieving pain associated with multiple sclerosis, four tablets each containing 19.5 milligrams of APM was ingested by a patient with multiple sclerosis. The dosage was repeated at 100-120 milligrams every six hours. Upon administration of the APM, the patient's need for opiates for relief from pain dropped by 50%: one-half tablet Percocet (Du Pont Pharmaceuticals, Wilmington, Del.; each tablet containing 5 mg oxycodone hydrochloride and 325 mg acetaminophen) taken 2-3 times a day rather than one tablet taken 4 times a day. By combining APM with the opiate analgesic, the required dosage of the opiate analgesic was decreased, thereby lessening the negative side effects of the opiate analgesic such as constipation experienced by the patient.

EXAMPLE 4

Alleviation of Pain Associated with Injury

APM provided pain relief for a 48 year old female (non-arthritic) who injured her heel and associated tendons and ligaments to the arch of the foot while running along rough terrain. At 12 hours after the injury, the patient walked with a severe limp. Approximately 4 packets (about 0.15 grams) APM mixed in orange juice was given to the patient on an empty stomach. Approximately 50 minutes later, the patient participated in a one mile hike without noticeable limp. A second 4-packet dose in orange juice was administered 5 hours later. Eight hours after start of treatment, the patient was walking without pain. The following morning, there was tenderness to thumb pressure but no pain while walking. Thirty-six hours after treatment, there was no pain and very little tenderness.

EXAMPLE 5

Alleviation of Pain Associated with Back Surgery

Enrolled in a blind study, an osteoarthritis patient was taking a study compound for pain relief. Prior to back surgery, the patient discontinued using the study compound, but postoperatively, he resumed taking five tablets of the study compound unprescribed three times a day. On Day 1 after surgery, the patient took only one prescribed p.r.n. pain tablet and discontinued use of a prescribed PCA pump narcotic pain reliever because he reported a lack of need. Despite continued access to prescribed pain relievers, the patient declined due to lack of need. The patient was walking on Day 1, went home on Day 3, and resumed normal routine without pain on Day 10. The blinded study compound was APM (19.5 milligrams per tablet).

EXAMPLE 6

Myocardial Infraction--Pain Alleviation

Pain associated with myocardial infarction has been associated with platelet aggregation. APM may be used to alleviate pain associated with myocardial infarction. 

We claim:
 1. A method of decreasing pain in a patient comprising administering to said patient in need of such treatment an effective amount of a composition comprising: ##STR1## where R is H or an alkyl containing 1 to 6 carbons to effect a reduction in perceived pain by said patient, wherein an effective amount of said composition is from about 80 milligrams to about 320 milligrams.
 2. A method of decreasing pain in a patient comprising administering to said patient in need of such treatment an effective amount of a composition comprising: ##STR2## where R is H or an alkyl containing 1 to 6 carbons to effect a reduction in perceived pain by said patient, wherein an effective amount of said composition is about 180 milligrams.
 3. A method of decreasing the dosage of a first analgesic medication in a patient for pain, comprising administering to said patient in need of such treatment an effective amount of a second compound comprising: ##STR3## where R is H or an alkyl containing 1 to 6 carbons to cause a reduction in perceived pain by said patient.
 4. The method of claim 3, wherein said first analgesic medication is selected from the group consisting of acetaminophen, phenacetin, aspirin, ibuprofen, phenylbutazone, indomethacin and derivatives, opiates and derivatives, piroxacam, and steroidal and nonsteroidal anti-inflammatory agents.
 5. The method of claim 3, wherein said effective amount of said second compound is from about 40 milligrams to about 540 milligrams.
 6. The method of claim 4, wherein said effective amount of said second compound is from about 40 milligrams to about 540 milligrams.
 7. The method of claim 3, wherein an effective amount of said second compound is that amount required to reduce the effective dosage of said first analgesic medication by about 25% to about 75%.
 8. The method of claim 4, wherein an effective amount of said second compound is that amount required to reduce the effective dosage of said first analgesic medication by about 25% to about 75%.
 9. The method of claim 3, wherein an effective amount of said second compound is that amount required to reduce the effective dosage of said first analgesic medication by about 10% to about 90%.
 10. The method of claim 4, wherein an effective amount of said second compound is that amount required to reduce the effective dosage of said first analgesic medication by about 10% to about 90%.
 11. A method for treating an osteoarthritis patient for pain, comprising the steps of: administering an effective amount of a composition comprising: ##STR4## where R is CH₃ to effect a reduction in perceived pain by said patient, wherein said composition is the sole active pain-relieving agent administered to said patient.
 12. A method of treating pain in a patient comprising administering to said patient in need of such treatment an effective pain-reducing amount of an active pain-relieving agent, wherein said active pain-relieving agent consists of a composition of the formula: ##STR5## where R is CH₃.
 13. The method of claim 12, wherein said effective amount is greater than 40 mg.
 14. The method of claim 12, wherein said effective amount is from about 80 mg to about 540 mg. 